Course of the Experiment

Zimbardo decided to conduct this experiment to study if good people could do terrible things when placed in bad circumstances. So, Zimbardo put an ad in the newspaper, and seventy men responded. Next, they went through a series of psychological tests and the healthiest twenty-four men were chosen to be randomly assigned prisoner or guard.  Before the experiment began, Zimbardo met with the guards for an initial orientation where he told them they could use any methods to dehumanize the prisoners, but could not harm them. However, this was not strictly enforced, and the guards severely abused the prisoners, which caused the study to be ended early. 

Throughout the course of this experiment, the guards became increasingly abusive towards the prisoners, which caused the study to be shut down after only six days.